3 * This is the MySQL database abstraction layer.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
23 namespace Wikimedia\Rdbms
;
27 use Wikimedia\AtEase\AtEase
;
28 use InvalidArgumentException
;
34 * Database abstraction object for MySQL.
35 * Defines methods independent on used MySQL extension.
41 abstract class DatabaseMysqlBase
extends Database
{
42 /** @var MysqlMasterPos */
43 protected $lastKnownReplicaPos;
44 /** @var string Method to detect replica DB lag */
45 protected $lagDetectionMethod;
46 /** @var array Method to detect replica DB lag */
47 protected $lagDetectionOptions = [];
48 /** @var bool bool Whether to use GTID methods */
49 protected $useGTIDs = false;
50 /** @var string|null */
51 protected $sslKeyPath;
52 /** @var string|null */
53 protected $sslCertPath;
54 /** @var string|null */
56 /** @var string|null */
58 /** @var string[]|null */
59 protected $sslCiphers;
60 /** @var string sql_mode value to send on connection */
62 /** @var bool Use experimental UTF-8 transmission encoding */
65 protected $defaultBigSelects = null;
67 /** @var string|null */
68 private $serverVersion = null;
70 private $insertSelectIsSafe = null;
71 /** @var stdClass|null */
72 private $replicationInfoRow = null;
74 // Cache getServerId() for 24 hours
75 const SERVER_ID_CACHE_TTL
= 86400;
77 /** @var float Warn if lag estimates are made for transactions older than this many seconds */
78 const LAG_STALE_WARN_THRESHOLD
= 0.100;
81 * Additional $params include:
82 * - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
83 * pt-heartbeat assumes the table is at heartbeat.heartbeat
84 * and uses UTC timestamps in the heartbeat.ts column.
85 * (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
86 * - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
87 * the default behavior. Normally, the heartbeat row with the server
88 * ID of this server's master will be used. Set the "conds" field to
89 * override the query conditions, e.g. ['shard' => 's1'].
90 * - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
91 * - insertSelectIsSafe : force that native INSERT SELECT is or is not safe [default: null]
92 * - sslKeyPath : path to key file [default: null]
93 * - sslCertPath : path to certificate file [default: null]
94 * - sslCAFile: path to a single certificate authority PEM file [default: null]
95 * - sslCAPath : parth to certificate authority PEM directory [default: null]
96 * - sslCiphers : array list of allowable ciphers [default: null]
97 * @param array $params
99 public function __construct( array $params ) {
100 $this->lagDetectionMethod
= $params['lagDetectionMethod'] ??
'Seconds_Behind_Master';
101 $this->lagDetectionOptions
= $params['lagDetectionOptions'] ??
[];
102 $this->useGTIDs
= !empty( $params['useGTIDs' ] );
103 foreach ( [ 'KeyPath', 'CertPath', 'CAFile', 'CAPath', 'Ciphers' ] as $name ) {
105 if ( isset( $params[$var] ) ) {
106 $this->$var = $params[$var];
109 $this->sqlMode
= $params['sqlMode'] ??
null;
110 $this->utf8Mode
= !empty( $params['utf8Mode'] );
111 $this->insertSelectIsSafe
= isset( $params['insertSelectIsSafe'] )
112 ?
(bool)$params['insertSelectIsSafe'] : null;
114 parent
::__construct( $params );
120 public function getType() {
124 protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix ) {
127 if ( $schema !== null ) {
128 throw $this->newExceptionAfterConnectError( "Got schema '$schema'; not supported." );
131 $this->server
= $server;
133 $this->password
= $password;
135 $this->installErrorHandler();
137 $this->conn
= $this->mysqlConnect( $this->server
, $dbName );
138 } catch ( Exception
$e ) {
139 $this->restoreErrorHandler();
140 throw $this->newExceptionAfterConnectError( $e->getMessage() );
142 $error = $this->restoreErrorHandler();
144 if ( !$this->conn
) {
145 throw $this->newExceptionAfterConnectError( $error ?
: $this->lastError() );
149 $this->currentDomain
= new DatabaseDomain(
150 strlen( $dbName ) ?
$dbName : null,
154 // Abstract over any insane MySQL defaults
155 $set = [ 'group_concat_max_len = 262144' ];
156 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
157 if ( is_string( $this->sqlMode
) ) {
158 $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode
);
160 // Set any custom settings defined by site config
161 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
162 foreach ( $this->connectionVariables
as $var => $val ) {
163 // Escape strings but not numbers to avoid MySQL complaining
164 if ( !is_int( $val ) && !is_float( $val ) ) {
165 $val = $this->addQuotes( $val );
167 $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
172 'SET ' . implode( ', ', $set ),
174 self
::QUERY_IGNORE_DBO_TRX | self
::QUERY_NO_RETRY
177 } catch ( Exception
$e ) {
178 throw $this->newExceptionAfterConnectError( $e->getMessage() );
182 protected function doSelectDomain( DatabaseDomain
$domain ) {
183 if ( $domain->getSchema() !== null ) {
184 throw new DBExpectedError(
186 __CLASS__
. ": domain '{$domain->getId()}' has a schema component"
190 $database = $domain->getDatabase();
191 // A null database means "don't care" so leave it as is and update the table prefix
192 if ( $database === null ) {
193 $this->currentDomain
= new DatabaseDomain(
194 $this->currentDomain
->getDatabase(),
196 $domain->getTablePrefix()
202 if ( $database !== $this->getDBname() ) {
203 $sql = 'USE ' . $this->addIdentifierQuotes( $database );
204 list( $res, $err, $errno ) =
205 $this->executeQuery( $sql, __METHOD__
, self
::QUERY_IGNORE_DBO_TRX
);
207 if ( $res === false ) {
208 $this->reportQueryError( $err, $errno, $sql, __METHOD__
);
209 return false; // unreachable
213 // Update that domain fields on success (no exception thrown)
214 $this->currentDomain
= $domain;
220 * Open a connection to a MySQL server
222 * @param string $realServer
223 * @param string|null $dbName
224 * @return mixed|null Driver connection handle
225 * @throws DBConnectionError
227 abstract protected function mysqlConnect( $realServer, $dbName );
230 * @param IResultWrapper|resource $res
231 * @throws DBUnexpectedError
233 public function freeResult( $res ) {
234 AtEase
::suppressWarnings();
235 $ok = $this->mysqlFreeResult( ResultWrapper
::unwrap( $res ) );
236 AtEase
::restoreWarnings();
238 throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
245 * @param resource $res Raw result
248 abstract protected function mysqlFreeResult( $res );
251 * @param IResultWrapper|resource $res
252 * @return stdClass|bool
253 * @throws DBUnexpectedError
255 public function fetchObject( $res ) {
256 AtEase
::suppressWarnings();
257 $row = $this->mysqlFetchObject( ResultWrapper
::unwrap( $res ) );
258 AtEase
::restoreWarnings();
260 $errno = $this->lastErrno();
261 // Unfortunately, mysql_fetch_object does not reset the last errno.
262 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
263 // these are the only errors mysql_fetch_object can cause.
264 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
265 if ( $errno == 2000 ||
$errno == 2013 ) {
266 throw new DBUnexpectedError(
268 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
276 * Fetch a result row as an object
278 * @param resource $res Raw result
281 abstract protected function mysqlFetchObject( $res );
284 * @param IResultWrapper|resource $res
286 * @throws DBUnexpectedError
288 public function fetchRow( $res ) {
289 AtEase
::suppressWarnings();
290 $row = $this->mysqlFetchArray( ResultWrapper
::unwrap( $res ) );
291 AtEase
::restoreWarnings();
293 $errno = $this->lastErrno();
294 // Unfortunately, mysql_fetch_array does not reset the last errno.
295 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
296 // these are the only errors mysql_fetch_array can cause.
297 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
298 if ( $errno == 2000 ||
$errno == 2013 ) {
299 throw new DBUnexpectedError(
301 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
309 * Fetch a result row as an associative and numeric array
311 * @param resource $res Raw result
312 * @return array|false
314 abstract protected function mysqlFetchArray( $res );
317 * @throws DBUnexpectedError
318 * @param IResultWrapper|resource $res
321 function numRows( $res ) {
322 if ( is_bool( $res ) ) {
325 AtEase
::suppressWarnings();
326 $n = $this->mysqlNumRows( ResultWrapper
::unwrap( $res ) );
327 AtEase
::restoreWarnings();
330 // Unfortunately, mysql_num_rows does not reset the last errno.
331 // We are not checking for any errors here, since
332 // there are no errors mysql_num_rows can cause.
333 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
334 // See https://phabricator.wikimedia.org/T44430
339 * Get number of rows in result
341 * @param resource $res Raw result
344 abstract protected function mysqlNumRows( $res );
347 * @param IResultWrapper|resource $res
350 public function numFields( $res ) {
351 return $this->mysqlNumFields( ResultWrapper
::unwrap( $res ) );
355 * Get number of fields in result
357 * @param resource $res Raw result
360 abstract protected function mysqlNumFields( $res );
363 * @param IResultWrapper|resource $res
367 public function fieldName( $res, $n ) {
368 return $this->mysqlFieldName( ResultWrapper
::unwrap( $res ), $n );
372 * Get the name of the specified field in a result
374 * @param IResultWrapper|resource $res
378 abstract protected function mysqlFieldName( $res, $n );
381 * mysql_field_type() wrapper
382 * @param IResultWrapper|resource $res
386 public function fieldType( $res, $n ) {
387 return $this->mysqlFieldType( ResultWrapper
::unwrap( $res ), $n );
391 * Get the type of the specified field in a result
393 * @param IResultWrapper|resource $res
397 abstract protected function mysqlFieldType( $res, $n );
400 * @param IResultWrapper|resource $res
404 public function dataSeek( $res, $row ) {
405 return $this->mysqlDataSeek( ResultWrapper
::unwrap( $res ), $row );
409 * Move internal result pointer
411 * @param IResultWrapper|resource $res
415 abstract protected function mysqlDataSeek( $res, $row );
420 public function lastError() {
422 # Even if it's non-zero, it can still be invalid
423 AtEase
::suppressWarnings();
424 $error = $this->mysqlError( $this->conn
);
426 $error = $this->mysqlError();
428 AtEase
::restoreWarnings();
430 $error = $this->mysqlError();
433 $error .= ' (' . $this->server
. ')';
440 * Returns the text of the error message from previous MySQL operation
442 * @param resource|null $conn Raw connection
445 abstract protected function mysqlError( $conn = null );
447 protected function wasQueryTimeout( $error, $errno ) {
448 // https://dev.mysql.com/doc/refman/8.0/en/client-error-reference.html
449 // https://phabricator.wikimedia.org/T170638
450 return in_array( $errno, [ 2062, 3024 ] );
453 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
454 $this->nativeReplace( $table, $rows, $fname );
457 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
458 $row = $this->getReplicationSafetyInfo();
459 // For row-based-replication, the resulting changes will be relayed, not the query
460 if ( $row->binlog_format
=== 'ROW' ) {
463 // LIMIT requires ORDER BY on a unique key or it is non-deterministic
464 if ( isset( $selectOptions['LIMIT'] ) ) {
467 // In MySQL, an INSERT SELECT is only replication safe with row-based
468 // replication or if innodb_autoinc_lock_mode is 0. When those
469 // conditions aren't met, use non-native mode.
470 // While we could try to determine if the insert is safe anyway by
471 // checking if the target table has an auto-increment column that
472 // isn't set in $varMap, that seems unlikely to be worth the extra
475 in_array( 'NO_AUTO_COLUMNS', $insertOptions ) ||
476 (int)$row->innodb_autoinc_lock_mode
=== 0
481 * @return stdClass Process cached row
483 protected function getReplicationSafetyInfo() {
484 if ( $this->replicationInfoRow
=== null ) {
485 $this->replicationInfoRow
= $this->selectRow(
488 'innodb_autoinc_lock_mode' => '@@innodb_autoinc_lock_mode',
489 'binlog_format' => '@@binlog_format',
496 return $this->replicationInfoRow
;
500 * Estimate rows in dataset
501 * Returns estimated count, based on EXPLAIN output
502 * Takes same arguments as Database::select()
504 * @param string|array $table
505 * @param string|array $var
506 * @param string|array $conds
507 * @param string $fname
508 * @param string|array $options
509 * @param array $join_conds
512 public function estimateRowCount( $table, $var = '*', $conds = '',
513 $fname = __METHOD__
, $options = [], $join_conds = []
515 $conds = $this->normalizeConditions( $conds, $fname );
516 $column = $this->extractSingleFieldFromList( $var );
517 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
518 $conds[] = "$column IS NOT NULL";
521 $options['EXPLAIN'] = true;
522 $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
523 if ( $res === false ) {
526 if ( !$this->numRows( $res ) ) {
531 foreach ( $res as $plan ) {
532 $rows *= $plan->rows
> 0 ?
$plan->rows
: 1; // avoid resetting to zero
538 public function tableExists( $table, $fname = __METHOD__
) {
539 // Split database and table into proper variables as Database::tableName() returns
540 // shared tables prefixed with their database, which do not work in SHOW TABLES statements
541 list( $database, , $prefix, $table ) = $this->qualifiedTableComponents( $table );
542 $tableName = "{$prefix}{$table}";
544 if ( isset( $this->sessionTempTables
[$tableName] ) ) {
545 return true; // already known to exist and won't show in SHOW TABLES anyway
548 // We can't use buildLike() here, because it specifies an escape character
549 // other than the backslash, which is the only one supported by SHOW TABLES
550 $encLike = $this->escapeLikeInternal( $tableName, '\\' );
552 // If the database has been specified (such as for shared tables), use "FROM"
553 if ( $database !== '' ) {
554 $encDatabase = $this->addIdentifierQuotes( $database );
555 $query = "SHOW TABLES FROM $encDatabase LIKE '$encLike'";
557 $query = "SHOW TABLES LIKE '$encLike'";
560 return $this->query( $query, $fname )->numRows() > 0;
564 * @param string $table
565 * @param string $field
566 * @return bool|MySQLField
568 public function fieldInfo( $table, $field ) {
569 $table = $this->tableName( $table );
570 $flags = self
::QUERY_SILENCE_ERRORS
;
571 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__
, $flags );
575 $n = $this->mysqlNumFields( ResultWrapper
::unwrap( $res ) );
576 for ( $i = 0; $i < $n; $i++
) {
577 $meta = $this->mysqlFetchField( ResultWrapper
::unwrap( $res ), $i );
578 if ( $field == $meta->name
) {
579 return new MySQLField( $meta );
587 * Get column information from a result
589 * @param resource $res Raw result
593 abstract protected function mysqlFetchField( $res, $n );
596 * Get information about an index into an object
597 * Returns false if the index does not exist
599 * @param string $table
600 * @param string $index
601 * @param string $fname
602 * @return bool|array|null False or null on failure
604 public function indexInfo( $table, $index, $fname = __METHOD__
) {
605 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
606 # SHOW INDEX should work for 3.x and up:
607 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
608 $table = $this->tableName( $table );
609 $index = $this->indexName( $index );
611 $sql = 'SHOW INDEX FROM ' . $table;
612 $res = $this->query( $sql, $fname );
620 foreach ( $res as $row ) {
621 if ( $row->Key_name
== $index ) {
626 return $result ?
: false;
633 public function strencode( $s ) {
634 return $this->mysqlRealEscapeString( $s );
641 abstract protected function mysqlRealEscapeString( $s );
643 public function addQuotes( $s ) {
644 if ( is_bool( $s ) ) {
645 // Parent would transform to int, which does not play nice with MySQL type juggling.
646 // When searching for an int in a string column, the strings are cast to int, which
647 // means false would match any string not starting with a number.
648 $s = (string)(int)$s;
650 return parent
::addQuotes( $s );
654 * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
659 public function addIdentifierQuotes( $s ) {
660 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
661 // Remove NUL bytes and escape backticks by doubling
662 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
666 * @param string $name
669 public function isQuotedIdentifier( $name ) {
670 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
673 protected function doGetLag() {
674 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
675 return $this->getLagFromPtHeartbeat();
677 return $this->getLagFromSlaveStatus();
684 protected function getLagDetectionMethod() {
685 return $this->lagDetectionMethod
;
691 protected function getLagFromSlaveStatus() {
692 $flags = self
::QUERY_SILENCE_ERRORS | self
::QUERY_IGNORE_DBO_TRX
;
693 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__
, $flags );
694 $row = $res ?
$res->fetchObject() : false;
695 // If the server is not replicating, there will be no row
696 if ( $row && strval( $row->Seconds_Behind_Master
) !== '' ) {
697 return intval( $row->Seconds_Behind_Master
);
706 protected function getLagFromPtHeartbeat() {
707 $options = $this->lagDetectionOptions
;
709 $currentTrxInfo = $this->getRecordedTransactionLagStatus();
710 if ( $currentTrxInfo ) {
711 // There is an active transaction and the initial lag was already queried
712 $staleness = microtime( true ) - $currentTrxInfo['since'];
713 if ( $staleness > self
::LAG_STALE_WARN_THRESHOLD
) {
714 // Avoid returning higher and higher lag value due to snapshot age
715 // given that the isolation level will typically be REPEATABLE-READ
716 $this->queryLogger
->warning(
717 "Using cached lag value for {db_server} due to active transaction",
718 $this->getLogContext( [
719 'method' => __METHOD__
,
721 'trace' => ( new RuntimeException() )->getTraceAsString()
726 return $currentTrxInfo['lag'];
729 if ( isset( $options['conds'] ) ) {
730 // Best method for multi-DC setups: use logical channel names
731 $data = $this->getHeartbeatData( $options['conds'] );
733 // Standard method: use master server ID (works with stock pt-heartbeat)
734 $masterInfo = $this->getMasterServerInfo();
735 if ( !$masterInfo ) {
736 $this->queryLogger
->error(
737 "Unable to query master of {db_server} for server ID",
738 $this->getLogContext( [
739 'method' => __METHOD__
743 return false; // could not get master server ID
746 $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
747 $data = $this->getHeartbeatData( $conds );
750 list( $time, $nowUnix ) = $data;
751 if ( $time !== null ) {
752 // @time is in ISO format like "2015-09-25T16:48:10.000510"
753 $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
754 $timeUnix = (int)$dateTime->format( 'U' ) +
$dateTime->format( 'u' ) / 1e6
;
756 return max( $nowUnix - $timeUnix, 0.0 );
759 $this->queryLogger
->error(
760 "Unable to find pt-heartbeat row for {db_server}",
761 $this->getLogContext( [
762 'method' => __METHOD__
769 protected function getMasterServerInfo() {
770 $cache = $this->srvCache
;
771 $key = $cache->makeGlobalKey(
774 // Using one key for all cluster replica DBs is preferable
775 $this->getLBInfo( 'clusterMasterHost' ) ?
: $this->getServer()
779 return $cache->getWithSetCallback(
781 $cache::TTL_INDEFINITE
,
782 function () use ( $cache, $key, $fname ) {
783 // Get and leave a lock key in place for a short period
784 if ( !$cache->lock( $key, 0, 10 ) ) {
785 return false; // avoid master connection spike slams
788 $conn = $this->getLazyMasterHandle();
790 return false; // something is misconfigured
793 // Connect to and query the master; catch errors to avoid outages
795 $flags = self
::QUERY_SILENCE_ERRORS | self
::QUERY_IGNORE_DBO_TRX
;
796 $res = $conn->query( 'SELECT @@server_id AS id', $fname, $flags );
797 $row = $res ?
$res->fetchObject() : false;
798 $id = $row ?
(int)$row->id
: 0;
799 } catch ( DBError
$e ) {
803 // Cache the ID if it was retrieved
804 return $id ?
[ 'serverId' => $id, 'asOf' => time() ] : false;
810 * @param array $conds WHERE clause conditions to find a row
811 * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
812 * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
814 protected function getHeartbeatData( array $conds ) {
815 // Query time and trip time are not counted
816 $nowUnix = microtime( true );
817 // Do not bother starting implicit transactions here
818 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
820 $whereSQL = $this->makeList( $conds, self
::LIST_AND
);
821 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
822 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
823 // percision field is not supported in MySQL <= 5.5.
825 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1",
827 self
::QUERY_SILENCE_ERRORS | self
::QUERY_IGNORE_DBO_TRX
829 $row = $res ?
$res->fetchObject() : false;
831 $this->restoreFlags();
834 return [ $row ?
$row->ts
: null, $nowUnix ];
837 protected function getApproximateLagStatus() {
838 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
839 // Disable caching since this is fast enough and we don't wan't
840 // to be *too* pessimistic by having both the cache TTL and the
841 // pt-heartbeat interval count as lag in getSessionLagStatus()
842 return parent
::getApproximateLagStatus();
845 $key = $this->srvCache
->makeGlobalKey( 'mysql-lag', $this->getServer() );
846 $approxLag = $this->srvCache
->get( $key );
848 $approxLag = parent
::getApproximateLagStatus();
849 $this->srvCache
->set( $key, $approxLag, 1 );
855 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
856 if ( !( $pos instanceof MySQLMasterPos
) ) {
857 throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
860 if ( $this->getLBInfo( 'is static' ) === true ) {
861 return 0; // this is a copy of a read-only dataset with no master DB
862 } elseif ( $this->lastKnownReplicaPos
&& $this->lastKnownReplicaPos
->hasReached( $pos ) ) {
863 return 0; // already reached this point for sure
866 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
867 if ( $pos->getGTIDs() ) {
868 // Ignore GTIDs from domains exclusive to the master DB (presumably inactive)
869 $rpos = $this->getReplicaPos();
870 $gtidsWait = $rpos ? MySQLMasterPos
::getCommonDomainGTIDs( $pos, $rpos ) : [];
872 $this->queryLogger
->error(
873 "No GTIDs with the same domain between master ($pos) and replica ($rpos)",
874 $this->getLogContext( [
875 'method' => __METHOD__
,
879 return -1; // $pos is from the wrong cluster?
881 // Wait on the GTID set (MariaDB only)
882 $gtidArg = $this->addQuotes( implode( ',', $gtidsWait ) );
883 if ( strpos( $gtidArg, ':' ) !== false ) {
884 // MySQL GTIDs, e.g "source_id:transaction_id"
885 $sql = "SELECT WAIT_FOR_EXECUTED_GTID_SET($gtidArg, $timeout)";
887 // MariaDB GTIDs, e.g."domain:server:sequence"
888 $sql = "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)";
891 // Wait on the binlog coordinates
892 $encFile = $this->addQuotes( $pos->getLogFile() );
893 $encPos = intval( $pos->getLogPosition()[$pos::CORD_EVENT
] );
894 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
897 list( $res, $err ) = $this->executeQuery( $sql, __METHOD__
, self
::QUERY_IGNORE_DBO_TRX
);
898 $row = $res ?
$this->fetchRow( $res ) : false;
900 throw new DBExpectedError( $this, "Replication wait failed: {$err}" );
903 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
904 $status = ( $row[0] !== null ) ?
intval( $row[0] ) : null;
905 if ( $status === null ) {
906 if ( !$pos->getGTIDs() ) {
907 // T126436: jobs programmed to wait on master positions might be referencing
908 // binlogs with an old master hostname; this makes MASTER_POS_WAIT() return null.
909 // Try to detect this case and treat the replica DB as having reached the given
910 // position (any master switchover already requires that the new master be caught
911 // up before the switch).
912 $replicationPos = $this->getReplicaPos();
913 if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
914 $this->lastKnownReplicaPos
= $replicationPos;
918 } elseif ( $status >= 0 ) {
919 // Remember that this position was reached to save queries next time
920 $this->lastKnownReplicaPos
= $pos;
927 * Get the position of the master from SHOW SLAVE STATUS
929 * @return MySQLMasterPos|bool
931 public function getReplicaPos() {
932 $now = microtime( true ); // as-of-time *before* fetching GTID variables
934 if ( $this->useGTIDs() ) {
935 // Try to use GTIDs, fallbacking to binlog positions if not possible
936 $data = $this->getServerGTIDs( __METHOD__
);
937 // Use gtid_slave_pos for MariaDB and gtid_executed for MySQL
938 foreach ( [ 'gtid_slave_pos', 'gtid_executed' ] as $name ) {
939 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
940 return new MySQLMasterPos( $data[$name], $now );
945 $data = $this->getServerRoleStatus( 'SLAVE', __METHOD__
);
946 if ( $data && strlen( $data['Relay_Master_Log_File'] ) ) {
947 return new MySQLMasterPos(
948 "{$data['Relay_Master_Log_File']}/{$data['Exec_Master_Log_Pos']}",
957 * Get the position of the master from SHOW MASTER STATUS
959 * @return MySQLMasterPos|bool
961 public function getMasterPos() {
962 $now = microtime( true ); // as-of-time *before* fetching GTID variables
965 if ( $this->useGTIDs() ) {
966 // Try to use GTIDs, fallbacking to binlog positions if not possible
967 $data = $this->getServerGTIDs( __METHOD__
);
968 // Use gtid_binlog_pos for MariaDB and gtid_executed for MySQL
969 foreach ( [ 'gtid_binlog_pos', 'gtid_executed' ] as $name ) {
970 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
971 $pos = new MySQLMasterPos( $data[$name], $now );
975 // Filter domains that are inactive or not relevant to the session
977 $pos->setActiveOriginServerId( $this->getServerId() );
978 $pos->setActiveOriginServerUUID( $this->getServerUUID() );
979 if ( isset( $data['gtid_domain_id'] ) ) {
980 $pos->setActiveDomain( $data['gtid_domain_id'] );
986 $data = $this->getServerRoleStatus( 'MASTER', __METHOD__
);
987 if ( $data && strlen( $data['File'] ) ) {
988 $pos = new MySQLMasterPos( "{$data['File']}/{$data['Position']}", $now );
997 * @throws DBQueryError If the variable doesn't exist for some reason
999 protected function getServerId() {
1000 $fname = __METHOD__
;
1001 return $this->srvCache
->getWithSetCallback(
1002 $this->srvCache
->makeGlobalKey( 'mysql-server-id', $this->getServer() ),
1003 self
::SERVER_ID_CACHE_TTL
,
1004 function () use ( $fname ) {
1005 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1006 $res = $this->query( "SELECT @@server_id AS id", $fname, $flags );
1008 return intval( $this->fetchObject( $res )->id
);
1014 * @return string|null
1016 protected function getServerUUID() {
1017 $fname = __METHOD__
;
1018 return $this->srvCache
->getWithSetCallback(
1019 $this->srvCache
->makeGlobalKey( 'mysql-server-uuid', $this->getServer() ),
1020 self
::SERVER_ID_CACHE_TTL
,
1021 function () use ( $fname ) {
1022 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1023 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'server_uuid'", $fname, $flags );
1024 $row = $this->fetchObject( $res );
1026 return $row ?
$row->Value
: null;
1032 * @param string $fname
1035 protected function getServerGTIDs( $fname = __METHOD__
) {
1038 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1039 // Get global-only variables like gtid_executed
1040 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_%'", $fname, $flags );
1041 foreach ( $res as $row ) {
1042 $map[$row->Variable_name
] = $row->Value
;
1044 // Get session-specific (e.g. gtid_domain_id since that is were writes will log)
1045 $res = $this->query( "SHOW SESSION VARIABLES LIKE 'gtid_%'", $fname, $flags );
1046 foreach ( $res as $row ) {
1047 $map[$row->Variable_name
] = $row->Value
;
1054 * @param string $role One of "MASTER"/"SLAVE"
1055 * @param string $fname
1056 * @return string[] Latest available server status row
1058 protected function getServerRoleStatus( $role, $fname = __METHOD__
) {
1059 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1061 return $this->query( "SHOW $role STATUS", $fname, $flags )->fetchRow() ?
: [];
1064 public function serverIsReadOnly() {
1065 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1066 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__
, $flags );
1067 $row = $this->fetchObject( $res );
1069 return $row ?
( strtolower( $row->Value
) === 'on' ) : false;
1073 * @param string $index
1076 function useIndexClause( $index ) {
1077 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
1081 * @param string $index
1084 function ignoreIndexClause( $index ) {
1085 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
1091 public function getSoftwareLink() {
1092 // MariaDB includes its name in its version string; this is how MariaDB's version of
1093 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
1094 // in libmysql/libmysql.c).
1095 $version = $this->getServerVersion();
1096 if ( strpos( $version, 'MariaDB' ) !== false ||
strpos( $version, '-maria-' ) !== false ) {
1097 return '[{{int:version-db-mariadb-url}} MariaDB]';
1100 // Percona Server's version suffix is not very distinctive, and @@version_comment
1101 // doesn't give the necessary info for source builds, so assume the server is MySQL.
1102 // (Even Percona's version of mysql doesn't try to make the distinction.)
1103 return '[{{int:version-db-mysql-url}} MySQL]';
1109 public function getServerVersion() {
1110 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
1111 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
1112 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
1113 if ( $this->serverVersion
=== null ) {
1114 $this->serverVersion
= $this->selectField( '', 'VERSION()', '', __METHOD__
);
1116 return $this->serverVersion
;
1120 * @param array $options
1122 public function setSessionOptions( array $options ) {
1123 if ( isset( $options['connTimeout'] ) ) {
1124 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1125 $timeout = (int)$options['connTimeout'];
1126 $this->query( "SET net_read_timeout=$timeout", __METHOD__
, $flags );
1127 $this->query( "SET net_write_timeout=$timeout", __METHOD__
, $flags );
1132 * @param string &$sql
1133 * @param string &$newLine
1136 public function streamStatementEnd( &$sql, &$newLine ) {
1137 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
1138 preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
1139 $this->delimiter
= $m[1];
1143 return parent
::streamStatementEnd( $sql, $newLine );
1147 * Check to see if a named lock is available. This is non-blocking.
1149 * @param string $lockName Name of lock to poll
1150 * @param string $method Name of method calling us
1154 public function lockIsFree( $lockName, $method ) {
1155 if ( !parent
::lockIsFree( $lockName, $method ) ) {
1156 return false; // already held
1159 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1161 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1162 $res = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method, $flags );
1163 $row = $this->fetchObject( $res );
1165 return ( $row->lockstatus
== 1 );
1169 * @param string $lockName
1170 * @param string $method
1171 * @param int $timeout
1174 public function lock( $lockName, $method, $timeout = 5 ) {
1175 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1177 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1178 $res = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method, $flags );
1179 $row = $this->fetchObject( $res );
1181 if ( $row->lockstatus
== 1 ) {
1182 parent
::lock( $lockName, $method, $timeout ); // record
1186 $this->queryLogger
->info( __METHOD__
. " failed to acquire lock '{lockname}'",
1187 [ 'lockname' => $lockName ] );
1194 * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1195 * @param string $lockName
1196 * @param string $method
1199 public function unlock( $lockName, $method ) {
1200 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1202 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1203 $res = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method, $flags );
1204 $row = $this->fetchObject( $res );
1206 if ( $row->lockstatus
== 1 ) {
1207 parent
::unlock( $lockName, $method ); // record
1211 $this->queryLogger
->warning( __METHOD__
. " failed to release lock '$lockName'\n" );
1216 private function makeLockName( $lockName ) {
1217 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1218 // Newer version enforce a 64 char length limit.
1219 return ( strlen( $lockName ) > 64 ) ?
sha1( $lockName ) : $lockName;
1222 public function namedLocksEnqueue() {
1226 public function tableLocksHaveTransactionScope() {
1227 return false; // tied to TCP connection
1230 protected function doLockTables( array $read, array $write, $method ) {
1232 foreach ( $write as $table ) {
1233 $items[] = $this->tableName( $table ) . ' WRITE';
1235 foreach ( $read as $table ) {
1236 $items[] = $this->tableName( $table ) . ' READ';
1239 $sql = "LOCK TABLES " . implode( ',', $items );
1240 $this->query( $sql, $method, self
::QUERY_IGNORE_DBO_TRX
);
1245 protected function doUnlockTables( $method ) {
1246 $this->query( "UNLOCK TABLES", $method, self
::QUERY_IGNORE_DBO_TRX
);
1252 * @param bool $value
1254 public function setBigSelects( $value = true ) {
1255 if ( $value === 'default' ) {
1256 if ( $this->defaultBigSelects
=== null ) {
1257 # Function hasn't been called before so it must already be set to the default
1260 $value = $this->defaultBigSelects
;
1262 } elseif ( $this->defaultBigSelects
=== null ) {
1263 $this->defaultBigSelects
=
1264 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__
);
1266 $encValue = $value ?
'1' : '0';
1267 $this->query( "SET sql_big_selects=$encValue", __METHOD__
, self
::QUERY_IGNORE_DBO_TRX
);
1271 * DELETE where the condition is a join. MySql uses multi-table deletes.
1272 * @param string $delTable
1273 * @param string $joinTable
1274 * @param string $delVar
1275 * @param string $joinVar
1276 * @param array|string $conds
1277 * @param bool|string $fname
1278 * @throws DBUnexpectedError
1280 public function deleteJoin(
1281 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1284 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
1287 $delTable = $this->tableName( $delTable );
1288 $joinTable = $this->tableName( $joinTable );
1289 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1291 if ( $conds != '*' ) {
1292 $sql .= ' AND ' . $this->makeList( $conds, self
::LIST_AND
);
1295 $this->query( $sql, $fname );
1298 public function upsert(
1299 $table, array $rows, $uniqueIndexes, array $set, $fname = __METHOD__
1301 if ( $rows === [] ) {
1302 return true; // nothing to do
1305 if ( !is_array( reset( $rows ) ) ) {
1309 $table = $this->tableName( $table );
1310 $columns = array_keys( $rows[0] );
1312 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1314 foreach ( $rows as $row ) {
1315 $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1317 $sql .= implode( ',', $rowTuples );
1318 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self
::LIST_SET
);
1320 $this->query( $sql, $fname );
1326 * Determines how long the server has been up
1330 public function getServerUptime() {
1331 $vars = $this->getMysqlStatus( 'Uptime' );
1333 return (int)$vars['Uptime'];
1337 * Determines if the last failure was due to a deadlock
1341 public function wasDeadlock() {
1342 return $this->lastErrno() == 1213;
1346 * Determines if the last failure was due to a lock timeout
1350 public function wasLockTimeout() {
1351 return $this->lastErrno() == 1205;
1355 * Determines if the last failure was due to the database being read-only.
1359 public function wasReadOnlyError() {
1360 return $this->lastErrno() == 1223 ||
1361 ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1364 public function wasConnectionError( $errno ) {
1365 return $errno == 2013 ||
$errno == 2006;
1368 protected function wasKnownStatementRollbackError() {
1369 $errno = $this->lastErrno();
1371 if ( $errno === 1205 ) { // lock wait timeout
1372 // Note that this is uncached to avoid stale values of SET is used
1373 $row = $this->selectRow(
1375 [ 'innodb_rollback_on_timeout' => '@@innodb_rollback_on_timeout' ],
1379 // https://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
1380 // https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html
1381 return $row->innodb_rollback_on_timeout ?
false : true;
1384 // See https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html
1385 return in_array( $errno, [ 1022, 1062, 1216, 1217, 1137, 1146, 1051, 1054 ], true );
1389 * @param string $oldName
1390 * @param string $newName
1391 * @param bool $temporary
1392 * @param string $fname
1395 public function duplicateTableStructure(
1396 $oldName, $newName, $temporary = false, $fname = __METHOD__
1398 $tmp = $temporary ?
'TEMPORARY ' : '';
1399 $newName = $this->addIdentifierQuotes( $newName );
1400 $oldName = $this->addIdentifierQuotes( $oldName );
1401 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1403 return $this->query( $query, $fname, $this::QUERY_PSEUDO_PERMANENT
);
1407 * List all tables on the database
1409 * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1410 * @param string $fname Calling function name
1413 public function listTables( $prefix = null, $fname = __METHOD__
) {
1414 $result = $this->query( "SHOW TABLES", $fname );
1418 foreach ( $result as $table ) {
1419 $vars = get_object_vars( $table );
1420 $table = array_pop( $vars );
1422 if ( !$prefix ||
strpos( $table, $prefix ) === 0 ) {
1423 $endArray[] = $table;
1431 * @param string $tableName
1432 * @param string $fName
1433 * @return bool|IResultWrapper
1435 public function dropTable( $tableName, $fName = __METHOD__
) {
1436 if ( !$this->tableExists( $tableName, $fName ) ) {
1440 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1444 * Get status information from SHOW STATUS in an associative array
1446 * @param string $which
1449 private function getMysqlStatus( $which = "%" ) {
1450 $flags = self
::QUERY_IGNORE_DBO_TRX
;
1451 $res = $this->query( "SHOW STATUS LIKE '{$which}'", __METHOD__
, $flags );
1454 foreach ( $res as $row ) {
1455 $status[$row->Variable_name
] = $row->Value
;
1462 * Lists VIEWs in the database
1464 * @param string|null $prefix Only show VIEWs with this prefix, eg.
1465 * unit_test_, or $wgDBprefix. Default: null, would return all views.
1466 * @param string $fname Name of calling function
1470 public function listViews( $prefix = null, $fname = __METHOD__
) {
1471 // The name of the column containing the name of the VIEW
1472 $propertyName = 'Tables_in_' . $this->getDBname();
1474 // Query for the VIEWS
1475 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1477 foreach ( $res as $row ) {
1478 array_push( $allViews, $row->$propertyName );
1481 if ( is_null( $prefix ) ||
$prefix === '' ) {
1485 $filteredViews = [];
1486 foreach ( $allViews as $viewName ) {
1487 // Does the name of this VIEW start with the table-prefix?
1488 if ( strpos( $viewName, $prefix ) === 0 ) {
1489 array_push( $filteredViews, $viewName );
1493 return $filteredViews;
1497 * Differentiates between a TABLE and a VIEW.
1499 * @param string $name Name of the TABLE/VIEW to test
1500 * @param string|null $prefix
1504 public function isView( $name, $prefix = null ) {
1505 return in_array( $name, $this->listViews( $prefix ) );
1508 protected function isTransactableQuery( $sql ) {
1509 return parent
::isTransactableQuery( $sql ) &&
1510 !preg_match( '/^SELECT\s+(GET|RELEASE|IS_FREE)_LOCK\(/', $sql );
1513 public function buildStringCast( $field ) {
1514 return "CAST( $field AS BINARY )";
1518 * @param string $field Field or column to cast
1521 public function buildIntegerCast( $field ) {
1522 return 'CAST( ' . $field . ' AS SIGNED )';
1526 * @return bool Whether GTID support is used (mockable for testing)
1528 protected function useGTIDs() {
1529 return $this->useGTIDs
;
1534 * @deprecated since 1.29
1536 class_alias( DatabaseMysqlBase
::class, 'DatabaseMysqlBase' );